At present, in various flat display devices, liquid crystal displays (LCDs) have become the mainstream products, and a backlight module is a main component of an LCD.
In a backlight module as illustrated by FIG. 1, a light guide plate 106 is an important component in the backlight module, and the main function of the light guide plate is to transform the point light source emitting from lamp 105 to a planar light source with high evenness.
As illustrated by FIG. 2a, in order to guarantee the optical coupling of the lamp 105 and the light guide plate 106, in the beginning of design, it is required that the lamp 105 and the light guide plate 106 contact closely with each other. However, as illustrated by FIG. 2b, the lamp 105 and the light guide plate 106 generally have an unexpected interval therebetween, which causes a part of the optical energy to lose.
The interval between the lamp 105 and the light guide plate 106 determine the amount of the optical energy obtained by the light guide plate 106; through testing, the consequence as illustrated by FIG. 3a and FIG. 3b can be obtained; FIG. 3a illustrates the irradiation consequence when the interval between the lamp 105 and the light guide plate 106 is 0 mm, FIG. 3b illustrates the irradiation consequence when the interval between the lamp 105 and the light guide plate 106 is 0.7 mm; it can be clearly seen from FIG. 3a and FIG. 3b that: the energy obtained by the light guide plate in FIG. 3a is higher than the energy obtained by the light guide plate in FIG. 3b. Analyzing in combination with specific data can obtain the consequence as illustrated by Table 1:
Interval between the lampand the light guide plate00.140.280.420.560.7Optical energy100%98.54%94.53%88.7%84.69%79.5%obtained by thelight guide plate